With regard to data stored in a database, there is a case where it is necessary to change acquisition methods of data for each definition section of the data. In a case of acquiring data from a database storing data of various sensor devices, when the sensor devices have been updated and so on, there is a necessity to acquire data after correcting the data depending on the time when the data has been created.
Patent Literature 1 discloses a technique to change a data acquisition definition by rewriting a data acquisition command to be issued to a database by an application using data, before transmitting the data acquisition command to the database, by use of a database language reissue device.
Further, Patent Literature 2 discloses a technique to maintain consistency when data is referred to from outside, in a case where it is necessary to change a definition of the data, by updating the definition of the data beforehand.